Management of Myocardial Infarction with Antiplatelet and Statin Therapy

Antiplatelet Therapy

The American College of Cardiology recommends a loading dose of 162-325 mg of aspirin for all patients with MI, regardless of whether they are receiving heparin 1, 2
For patients who cannot take oral medications, the European Society of Cardiology suggests intravenous aspirin at a dose of 250-500 mg can be administered 4
The American Heart Association recommends aspirin be continued indefinitely at a maintenance dose of 81-325 mg daily, with 81 mg being the preferred maintenance dose 2, 3
For STEMI patients, the American College of Cardiology recommends a loading dose of clopidogrel based on the timing of PCI: 300 mg if PCI is planned within 24 hours of fibrinolytic therapy, and 600 mg if PCI is planned more than 24 hours after fibrinolytic therapy 1, 2
For patients with NSTEMI/unstable angina, the American Heart Association recommends a 300-600 mg loading dose of clopidogrel 5

The European Society of Cardiology recommends high-intensity statin therapy be initiated or continued as early as possible in patients with acute MI 6
Early statin therapy (within 24-72 hours) after admission for acute coronary syndrome has been associated with improved outcomes, according to the European Heart Journal 6
The American College of Cardiology states there are no contraindications to initiating statin therapy in patients already receiving heparin 1, 2

For patients who may require urgent CABG, the American Heart Association recommends aspirin should not be withheld, and clopidogrel should ideally be discontinued at least 24 hours before urgent on-pump CABG if possible 2
For patients receiving GP IIb/IIIa inhibitors along with heparin, the American College of Cardiology recommends the activated clotting time (ACT) should be maintained at 200-250 seconds 3
Without GP IIb/IIIa inhibitors, the American Heart Association recommends ACT should be maintained at 250-300 seconds (HemoTec) or 300-350 seconds (Hemochron) 2

When patients are already on heparin, the American College of Cardiology recommends continuing unfractionated heparin (UFH) through PCI, administering additional IV boluses as needed to maintain therapeutic ACT 2, 3
For enoxaparin, the American Heart Association recommends no additional dose if last dose was within previous 8 hours; 0.3 mg/kg IV bolus if last dose was 8-12 hours earlier 2, 3
The American College of Cardiology states fondaparinux should not be used as the sole anticoagulant for PCI due to risk of catheter thrombosis 2

The American Heart Association recommends the loading doses of antiplatelet agents should be administered as soon as possible after the diagnosis of MI is established 7, 8